3 types of flooring to tile over advice needed

[steve mason]

Im off to look at a flooring job on sunday so could do with some advice. They want slate laying over 25m2 running from the hall (floor boards) into a laundry room (concrete) into a new kitchen extention (woodchip boards). I was thinking of laying 12mm ply in the hall and kitchen and then putting slc in the laundry room to bring it upto the same level. Ive never used slc before so tips on this would be good.

[tileexperts]

yes i would lay the 12mm ply as you said, and make up the level in the concrete part. or you could put ply on the concrete too and use hammer in fixings but. it will take you a while to do this???. maybe am wrong.

plenty of scews and a nice flexi adhesive on the ply

[timeless john]

First establish how secure/braced and level are your two wood areas and if rigid fix hardie backer boards throughout.
Flexible adhesive and screws to fix boards - flexible adhesive/grout to fix tiles.
And at 6mm thick reduces your overall height.
Use full boards on all walkway areas and bridge between floor areas to overcome expansion in substrate. Tape all joints in boards.


Timeless John.

[Dave]

You should really put a movement joint where the substrates type changes ...different substrates expand and contract at different rates and could cause delamination of the tiles and stress cracks....

[steve mason]

First establish how secure/braced and level are your two wood areas and if rigid fix hardie backer boards throughout.
Flexible adhesive and screws to fix boards - flexible adhesive/grout to fix tiles.
And at 6mm thick reduces your overall height.
Use full boards on all walkway areas and bridge between floor areas to overcome expansion in substrate. Tape all joints in boards.


Timeless John.

I take it you mean fix boards with flex adi onto the concrete and screw into the boards? Why do i need to tape all the joints and what type of tape? ( sorry for questions, never used hardie backer board) Is 6mm as strong as 12mm ply then?

[steve mason]

You should really put a movement joint where the substrates type changes ...different substrates expand and contract at different rates and could cause delamination of the tiles and stress cracks....

Cheers dave, ive never used a movement joint before as only laid onto the same type of substrate. How do i put it in? i presume i fit it inbetween the hardie backer board as it runs into the next substrate. Do you know if ctd sell these?

[whitebeam]

Use plasterers scrim for the joints

[grumpygrouter]

I take it you mean fix boards with flex adi onto the concrete and screw into the boards? Why do i need to tape all the joints and what type of tape? ( sorry for questions, never used hardie backer board) Is 6mm as strong as 12mm ply then?

No, it isn't a substitue as a strengthener, and that is why John said to make sure the floor is strong enough. it does give a more "stable" surface to tile onto though.

[steve mason]

Thanks guys for the advice, off to look at the job tonight feel alot more confident now.